The invention relates to an apparatus for producing granules or pastils from flowable material.
Such an apparatus is known from DE-GM 1,796,248. In this known apparatus a relatively highly viscous starting material is introduced above the pressing nip between the hollow roll and the ejection roll, a wipe-in metal plate being provided which strokes the material into the teeth gaps of the internal toothing of the hollow roll, from which it is pressed out through the bores with the aid of the external toothing of the pressing roll and discharged from the hollow roll. With low-viscosity material a wipe-in metal plate may be dispensed with because such material automatically flows into the pressing nip and is expelled through the exit bores of the hollow roll. This known apparatus further provides that, by changing the spacing of the rotation axes of the ejection roll and the hollow roll, the pressing pressure can be varied to change the size and form of the granules or pastils produced in dependence upon the viscosity. For this adjustment of the position of the ejection roll, a certain adaptation to material of different viscosity is thus also possible. However, this adaptation is possibly only over a certain range of viscosity values, and in many cases it is desirable to increase this viscosity value range or to influence the size of the pastils or granules in another manner. For this purpose, in the known apparatus the ejection roll is mounted in vertically adjustable rotary bearings whilst the hollow roll carries races arranged at the outer periphery and cooperating with the bearing rollers. At the outer periphery of the hollow roll a toothing is arranged which is in engagement with drive means which drive the hollow roll and via the internal and external toothing also drive the ejection roll in rotation. Since the ejection roll is mounted eccentrically to the hollow roll, said hollow roll must either be formed as a cylinder jacket or at least be formed with relatively large openings at the end sides to permit rotation or the hollow roll without interference from the rotation shaft of the ejection roll. As a result, the flowable material in the interior of the hollow roll is in permanent contact with the ambient air and this may be undesirable with certain materials.